Nonwoven fabrics and fabric laminates from multiconstituent fibers

A nonwoven fabric laminate comprising:

• first and second thermally bonded spunbonded webs of multiconstituent fiber, and at least one microfibrous web disposed between said first and second spunbonded webs, the multiconstituent fiber of said first and second spunbonded webs comprising continuous filaments formed of a highly dispersed blend of at least two different thermoplastic polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, the polymer of said at least one noncontinuous phase having a melting temperature below that of said continuous phase, wherein said multiconstituent fibers are configured such that said at least one noncontinuous phase occupies a substantial portion of the fiber surfaces;
• and
• a multiplicity of thermal bonds formed in said spunbonded webs from the polymer of said multiconstituent fiber thereof, said thermal bonds bonding the continuous filaments of the spunbonded webs to one another and also bonding the spunbonded webs to said at least one microfibrous web, said multiconstituent fiber exhibiting deformation and polymer flow in the vicinity of its juncture with said thermal bonds.

A nonwoven fabric laminate comprising:

• first and second thermally bonded spunbonded webs of multiconstituent fiber, and at least one meltblown microfibrous polypropylene web disposed between said first and second spunbonded webs, the multiconstituent fiber of said first and second thermally bonded spunbonded webs comprising continuous filaments formed of a highly dispersed blend of thermoplastic olefin polymers, including isotactic polypropylene present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyethylene polymer forming a noncontinuous phase dispersed in said continuous polypropylene phase, wherein said multiconstituent fibers are configured such that said noncontinuous polyethylene phase occupies a substantial portion of the fiber surfaces;
• and
• a multiplicity of discrete thermal bonds formed in said spunbonded webs from the polymer of said multiconstituent fiber thereof, said thermal bonds bonding the continuous filaments of the spunbonded webs to one another and also bonding the spunbonded webs to said at least one meltblown microfibrous polypropylene web, said multiconstituent fiber exhibiting deformation and polymer flow in the vicinity of its juncture with said thermal bonds.

A nonwoven fabric laminate comprising:

• first and second spunbonded webs of multiconstituent fiber, and at least one meltblown microfibrous polypropylene web disposed between said first and second spunbonded webs, the multiconstituent fiber of said first and second thermally bonded spunbonded webs comprising continuous filaments formed of a highly dispersed blend of a polyamide polymer present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyethylene polymer forming a noncontinuous phase dispersed in said continuous polyamide phase;
• and
• a multiplicity of discrete thermal bonds formed in said spunbonded webs from the polymer of said multiconstituent fiber thereof, said thermal bonds bonding the continuous filaments of the spunbonded webs to one another and also bonding the spunbonded webs to said at least one meltblown microfibrous polypropylene web.

A nonwoven fabric laminate comprising:

• first and second spunbonded webs of multiconstituent fiber, and at least one meltblown microfibrous polypropylene web disposed between said first and second spunbonded webs, the multiconstituent fiber of said first and second thermally bonded spunbonded webs comprising continuous filaments formed of a highly dispersed blend of a polyester polymer present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyethylene polymer forming a noncontinuous phase dispersed in said continuous polyester phase;
• and
• a multiplicity of discrete thermal bonds formed in said spunbonded webs from the polymer of said multiconstituent fiber thereof, said thermal bonds bonding the continuous filaments of the spunbonded webs to one another and also bonding the spunbonded webs to said at least one meltblown microfibrous polypropylene web.

A thermally bonded nonwoven fabric comprising multiconstituent fibers formed of a highly dispersed blend of at least two different thermoplastic polymers which are present as a dominant continuous phase and at least one noncontinuous phase dispersed therein, the polymer of said at least one noncontinuous phase having a melting temperature below that of said continuous phase, and said lower melting noncontinuous phase comprising from about 2.5 to about 20 percent by weight of the fiber, wherein said multiconstituent fibers are configured such that said at least one noncontinuous phase occupies a substantial portion of the fiber surfaces;

• and a multiplicity of thermal bonds formed from the polymer of said multiconstituent fibers and bonding the multiconstituent fibers to one another, said multiconstituent fiber exhibiting deformation and polymer flow in the vicinity of its juncture with said thermal bonds.

A thermally bonded nonwoven fabric comprising a spunbonded web of multiconstituent continuous filaments formed of a highly dispersed blend of thermoplastic olefin polymers, including isotactic polypropylene present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyethylene polymer forming a noncontinuous phase dispersed in said continuous polypropylene phase, wherein said multiconstituent fibers are configured such that said noncontinuous polyethylene phase occupies a substantial portion of the fiber surfaces;

• and a multiplicity of discrete thermal bonds formed in said spunbonded web from the polymer of said multiconstituent filaments thereof bonding the continuous filaments of the spunbonded webs to one another, said multiconstituent fiber exhibiting deformation and polymer flow in the vicinity of its juncture with said thermal bonds.

A nonwoven fabric comprising a spunbonded web of multiconstituent continuous filaments formed of a highly dispersed blend of a polyamide polymer present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyolefin polymer forming a noncontinuous phase dispersed in said continuous polyamide phase;

• and a multiplicity of discrete thermal bonds formed in said spunbonded web from the polymer of said multiconstituent filaments thereof bonding the continuous filaments of the spunbonded webs to one another.

A nonwoven fabric comprising a spunbonded web of multiconstituent continuous filaments formed of a highly dispersed blend of a polyester polymer present as a dominant continuous phase and from about 2.5 to 20 percent by weight of a lower melting polyolefin polymer forming a noncontinuous phase dispersed in said continuous polyester phase;

• and a multiplicity of discrete thermal bonds formed in said spunbonded web from the polymer of said multiconstituent filaments thereof bonding the continuous filaments of the spunbonded webs to one another.